LDS cylinder head - resurfacing questions

[cattlerepairman]

So the machine shop has my heads and they panic a little (I thought they did plenty of trucks and tractors, but maybe not). First, they were concerned about cracks. I supplied the pertinent info out of the LDS troubleshooting manual (cracks typically in two locations, between valve seats and around injector port; OK if no penetration into water jacket on pressure test). Now they question whether any material can be removed from the bottom at all, because there is not much there (in comparison to a small block Ford I guess).

My information is that 0.002 inches (2 Thousands) can be removed and that warps of 0.004 or more are the wear limit. I also think that the valves need to be set back the same amount that was removed at the bottom.
Can anyone confirm this or point to a source with this information?

 

[frank8003]

I just reviewed this again
http://www.steelsoldiers.com/showthread.php?48620-Head-gasket-repair-walk-through
That posting I thought would answer ALL the questions.
41+ url links to read.
We all must get cattlerepairman a definitive answer
Down at .002" to .005" it gets ground off.
I would like to see pictures of machining process Please.
OK I go read the LDS manual again.
I ground a lot of metal but never a engine head.

Is the new to be installed head gaskets have a recommeded surface finish in the instructions?
Any real shop would have a profilometer and be able to take minimum to get heads flat and deliver the surface finsh you specify.

If you went thru all that work to get it right then it is time to resurface the heads.How is this opinion?

View attachment LDS grind head how much 09022015.pdf

and from http://www.enginebuildermag.com/200...avoid-when-resurfacing-cylinder-heads-blocks/


As a rule, the recommended surface finish for a traditional composition style soft-face head gasket in an engine with cast iron heads and block is 60 to 120 microinches Ra (roughness average).

 

[cattlerepairman]

The heads come off a Continental-rebuilt LDS-465-1A. The engine is definitely rebuilt, because the rod and main bearings are 0.20 oversized. I have no way of knowing if the heads were also re-surfaced during the rebuild (or if the engine is on its fifth or ninth head gasket...). My understanding is that "rebuilt" means that the engine was completely stripped and then put together with all SERVICEABLE parts (not necessarily NEW). For example, one head has minimal wear on all valve guides, but the other one has all worn valve guides. I suspect that one head was new and the other was "still serviceable" when put on.

The shop is asking what the specs are for the head so they can determine if there is sufficient "meat" left to shave off.
I get that, on an otherwise ok head, you can take 0.002 off - maybe again, at another time - but surely not as often as you want. What does one measure to determine whether the heads are still re-surfeceable/refaceable or whether they are done, finished, kaput?

 

[dmetalmiki]

Well the only thing you (they) should "measure" (check) is, Are the heads straight and parallel. Viz. Not Warped. If they are ok in this respect, that negates re-surfacing. (if it ain't bust..don't fix it logic).

 

[cattlerepairman]

I finally managed to talk to a coherent individual and their concern is that they need to weld three cracks, which always causes some amount of warpage. They then resurface. They are not concerned that they will take away so much material that they cut into the coolant passages, but they want to avoid grinding into the valve seats (or leaving too little material over them) which could cause them to fall out.
They don't want to do all the work, only to find that the head is not serviceable. The shop insists that there must be measurements for thickness etc. that indicate the limit of useability for the application or clearly specifies how much material can be removed.
I read and read but the manuals are silent on this.

 

[frank8003]

Three hours and I have NOT found the serviceability standards for any dimension on the heads to grind them too.
Is it a TD block? Is it possible to find any difference in the height of the two heads at present time. One would think that both heads should be the same depth to valves (depth mikes) give or take a .001"

I did find in post #20 + #44 in this thread http://www.steelsoldiers.com/showth...-engine-overhaul-including-head-gaskets/page2
some interesting information.
One would wish for Zout or "G" or WillWagner or the Deuce Doctor to advise.
I don't like it when I can't find the data I need.
Does anybody have the blueprints for sale?

 

[rustystud]

OK here is how you can determine how much you can remove from a head. Since a diesel head's surface is flat you must also take the same amount of material from the valve face. So the limiting factor is the valve face itself. You can measure the valve insert to determine how much can safely be removed from the heads surface. I am unable to download the page from the manual ( TM 9-2815-210-35 page 218 ) as my computer's motherboard took a dump on me yesterday. Probably due to the high voltage from my MEP-002A which blew it's regulator saturday (power went out for 2 days) . The way you measure the valve face is to measure the total height of the installed valve. This measurement should NOT exceed 6.104" for the intake valve or 6.086" for the exhaust valve. You measure from the top of the valve "face" to the end of the valve stem. Knowing this measurement will allow you to know how much can safely be removed from the heads surface.
Sorry Frank that I'm not "Zout or G or WillWagner or the Deuce Doctor" . I'm just "rustystud".

Forgot to add that the maximum clearance between a straight edge and the head is 0.005" lengthwise and 0.003" crosswise at the center of the head.

 

[Floridianson]

Thought one of the TM's stated something about if the head was taken down before they were to mark it on the head and it was not to be redone again.

 

[cattlerepairman]

Passed this info on to the shop. Now let's see what they say. IF, Plan B, I need replacement heads, I suspect the LDS heads are not exactly the same as LDT heads? At least need to use the LDS valves and springs?

 

[frank8003]

My post was not meant as affront to any SS member or in fact anybody.
The comment in the post was to get those that "know" to please give a valid solution as this bit of information is rather elusive. It worked.
Thank You rustystud.

And, Oh, the elusive TM 9-2815-210-35 found nowhere, even using google + other search engines, is found in the SS Deuce TM's database? no.
It is noted here and note rustystud efforts for the good of all.
http://www.steelsoldiers.com/showthread.php?123958-I-ve-got-a-printed-copy-of-TM-9-2815-210-35

and this very interesting thread too
http://www.steelsoldiers.com/showth...-CFM-flow-Porting-the-heads-Tech-babble/page2

 

[rustystud]

Your welcome Frank. I came by that manual after years of searching on ebay and craigslist. If I remember right it was from a guy in Ohio who was selling off his fathers collection of military stuff. I did try and get it downloaded into digital form but they wanted over $300.00 to do it.

 

[gimpyrobb]

Passed this info on to the shop. Now let's see what they say. IF, Plan B, I need replacement heads, I suspect the LDS heads are not exactly the same as LDT heads? At least need to use the LDS valves and springs?

Do you have the old valve springs that are the same size all the way, or do you have the current ones that start small and get thicker? Might want to checkinto that too.

 

[rustystud]

View attachment Scan0001.pdfView attachment Scan0002.pdfI was finally able to upload some pages from my manual. I'm using my Toughbook laptop that "Tim" (tim292stro) helped me pick-out and upgrade. It is a learning curve I have to say.

 

[cattlerepairman]

Allright, so we shall see. One head is ok, the other needs to have cracks fused in three locations. Over-the-thumb quote is running at about $600. No choice, really.

I don't have the heads, so can't check which valve springs they have. Is it crucial to swap for the new style?

 

[gimpyrobb]

No just nice to have the latest stuff. For that price you might be able to find new heads. I'd send a PM to wildchild in Mi and ask him where he got his.

 

[cattlerepairman]

No just nice to have the latest stuff. For that price you might be able to find new heads. I'd send a PM to wildchild in Mi and ask him where he got his.

NEW for that price would be awesome. For "good, used", from what I found, it's close, price-wise. A good used LDT head is, what, about $150-200? I've seen them up to $300. Then there is shipping (and they sure are heavy!). Then I still have to swap the LDT stuff for LDS valves and springs, have it hot tanked and refinished - and hope that, after a detailed inspection, the "new" used head is indeed in much better shape than mine.
I will still check - I have a second engine (LDT) that I'd like to rebuild, once it is out of the truck (and my bank account has recovered from the current rebuild).

 

[rustystud]

NEW for that price would be awesome. For "good, used", from what I found, it's close, price-wise. A good used LDT head is, what, about $150-200? I've seen them up to $300. Then there is shipping (and they sure are heavy!). Then I still have to swap the LDT stuff for LDS valves and springs, have it hot tanked and refinished - and hope that, after a detailed inspection, the "new" used head is indeed in much better shape than mine.
I will still check - I have a second engine (LDT) that I'd like to rebuild, once it is out of the truck (and my bank account has recovered from the current rebuild).

You sure are doing everything by the book on this rebuild ! Yes it is costing a bit of money but you will have a great engine afterwards ! Good work !

 

[brianp454]

Your welcome Frank. I came by that manual after years of searching on ebay and craigslist. If I remember right it was from a guy in Ohio who was selling off his fathers collection of military stuff. I did try and get it downloaded into digital form but they wanted over $300.00 to do it.

If you have something scanned I can do it for you. I scanned one for someone on here a few months ago. I live in N Portland so we're not that far away. We're actually going mushroom hunting not for from you in a couple hours.

I've been meaning to touch base with you on a few other things. I'll write more when I get a chance, up early to clean the garage while the family is asleep.

I've also tried sending PM's and have nothing but trouble. Please email me at brianp454@yahoo.com

-Brian

 

[rustystud]

If you have something scanned I can do it for you. I scanned one for someone on here a few months ago. I live in N Portland so we're not that far away. We're actually going mushroom hunting not for from you in a couple hours.

I've been meaning to touch base with you on a few other things. I'll write more when I get a chance, up early to clean the garage while the family is asleep.

I've also tried sending PM's and have nothing but trouble. Please email me at brianp454@yahoo.com

-Brian

I am unable to email at this time as my main account information is all on my main computer and the motherboard took a dump on me last saturday. I have tried to get my laptop going but so far "no joy" . Try and PM me again. My account is not full so it should go through.

 

[SCSG-G4]

Yes, the TM 9-2815-210-35 manual would be a welcome addition. I just got through looking and I have the -34-1, the -34-2-1, the -34-2-2, and the 34P, but no -35.